What is CVE-2026-71858?

CVE-2026-71858 is Notepad++: shortcuts.xml Macro HMAC Bypass Enables Conditional Elevated Command Execution. The supplied enrichment data classifies it as Remote Code Exec mapped to CWE-78 OS Command Injection; CWE-345 CWE-345; CWE-693 CWE-693.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-71858. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-71858 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

2 public PoC repositories reported; 0 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with EDR process telemetry, host service logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-71858 using CVSS 5.4, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

mediumRemote Code Execpublic exploit

CVE-2026-71858

CVE-2026-71858 — Notepad++: shortcuts.xml Macro HMAC Bypass Enables Conditional Elevated Command Execution

Notepad++ is a free and open-source source code editor. Prior to 8.9.7, macros loaded from an attacker-controlled shortcuts.xml bypass the HMAC validation applied to UserDefinedCommands and can invoke Scintilla actions and the internal Open in Default Viewer command in an elevated Notepad++ process, allowing protected file modification and conditional elevated command execution when a local attacker influences settingsDir and a user triggers the macro. This issue is fixed in version 8.9.7.

Published Aug 17, 2026Updated Aug 17, 2026Sources: NVD, notepad-plus-plus (CNA), GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Exploit code

public exploit, none observed

EPSS

ahead of 0% of scored CVEs

Affects

notepad-plus-plus

CVSS base

5.4

medium

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

PoC

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade notepad-plus-plus to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
notepad-plus-plus	notepad-plus-plus	< 8.9.7	Vulnerable

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
5.4	CVSS 4.0	medium	—	—	notepad-plus-plus (CNA)

CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-693 · Protection Mechanism Failure

Bypass Protection Mechanism::

CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Execute Unauthorized Code or Commands
DoS: Crash, Exit, or Restart
Read Files or Directories
Modify Files or Directories

Mitigation: If at all possible, use library calls rather than external processes to recreate the desired functionality.

Weakness & attack patterns

CWE-78OS Command Injection
CWE-345
CWE-693

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-15 · Command DelimitersCAPEC-88 · OS Command InjectionCAPEC-43 · Exploiting Multiple Input Interpretation LayersCAPEC-108 · Command Line Execution through SQL InjectionCAPEC-6 · Argument Injection

T1557.002Adversary-in-the-Middle: ARP Cache Poisoning
T1584.002Compromise Infrastructure: DNS Server
T1491Defacement

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Monitor for scanner or exploit-pattern traffic after 2 public PoC repositories were reported.

EDR process telemetryhost service logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 5.4
Aug 17, 2026 · NVD
Initial · CVE published
Aug 17, 2026 · NVD

References

3 on the record

github.com/notepad-plus-plus/notepad-plus-plus/commit/7686e5a3025eaf1fb8e024c2ceb54670ea05f5fb
Exploit, Third Party Advisory, Mitre
github.com/notepad-plus-plus/notepad-plus-plus/releases/tag/v8.9.7
Exploit, Third Party Advisory, Mitre
github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-f4rj-vqq4-wvg4
Exploit, Third Party Advisory, Mitre

Elsewhere on this site

notepad-plus-plusevery CVE for this vendor
Remote Code Execsame class
CWE-78other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-71858 is Notepad++: shortcuts.xml Macro HMAC Bypass Enables Conditional Elevated Command Execution, a medium vulnerability affecting notepad-plus-plus from notepad-plus-plus. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-71858. Public exploit evidence is: 2 public PoC repositories reported; 0 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 5.4 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.